Dialysis is a common treatment used to assist patients suffering from a wide variety of kidney problems including severe late stage renal insufficiency which usually results in total or near total kidney failure. This treatment cleans the blood and removes waste products and excess water from the body, a task normally performed by healthy kidneys. Presently, there are two main types of dialysis that are performed to compensate for kidney failure, namely hemodialysis and peritoneal dialysis.
In hemodialysis, the patient's blood is generally passed through a form of artificial kidney in order to cleanse it, followed by the return of the blood to the patient's bloodstream. In peritoneal dialysis, the patient's own peritoneum is used as a semi-permeable membrane in order to remove waste products, and this procedure is carried out by filling the peritoneal cavity with a dialysis solution, also known as dialysate, which preferably is introduced into the body via a permanently implanted catheter. In this process, waste products such as urea and creatinine, as well as excess water, pass from the blood through the peritoneum into the peritoneal dialysis solution, and after a given period of time, or dwell, the used dialysis solution or spent dialysate may be removed from the peritoneal cavity and then either discarded or purified for reuse. In general, the removal of the spent dialysate may be accomplished from a permanent catheter implanted in the body.
Due to the importance of the catheters in carrying out dialysis procedures, it is vitally important that the multiple connections involved in such processes be secure, leak-proof, properly aligned, and easily connectable. This is particularly important using certain catheters which need to be manually connected following implantation into a patient. In addition, since many of these devices are intended for use by a patient on an outpatient basis such as in the home without the supervision of a healthcare professional, it is important that the connections remain secure and in proper position so that there is no leakage or improper delivery of dialysis fluid. It is thus important that such connections be made as simple and effectively as possible so that secure and mistake-proof connections can readily be made manually following implantation of the catheter into a patient. Accordingly, there is a strong need to develop secure, user-friendly catheter connections and connection adapters which can be utilized with dialysis equipment including those units designed for home care on an outpatient basis.
Traditionally, dialysis systems have used catheters with a single lumen wherein the dialysis fluid is introduced into and removed from the patient via the same tube. However, more recently, many dialysis systems now employ multiple lumen catheters wherein it is possible to introduce dialysis fluid through at least one of the lumens and remove the spent dialysate through another lumen in the same catheter. An example of such a multiple lumen system is the dual lumen catheter disclosed in WO 02/30489, incorporated herein by reference, wherein a catheter is described in which dialysate flows through a first lumen into the patient and spent dialysate simultaneously flows out through a second lumen. Other multiple lumen catheters have been disclosed for example in patent references including U.S. Pat. Nos. 4,950,259; 5,053,023; 5,167,623; 5,961,485; 5,868,717; 5,683,640; 5,486,159; 5,480,380; 5,380,276; 5,188,593; 5,156,592; 5,057,073; 5,009,636; 5,976,103; 5,961,486; 5,827,237; 5,569,182; 5,221,255; 4,842,582; 4,623,327; and 5,346,471; PCT references WO 94/05363 and 96/29111; European Patent Application 333308; German Patent application 10042067; and Japanese Patent references 8-206216; 2-116380 and 1-303159; all of these patent references incorporated herein by reference.
Although these multiple lumen catheters may increase the efficiency of the dialysis process, they create additional problems with regard to the multiple connections between the dialysis equipment, the lumens of the catheter providing inflow and outflow, and the patient. With such multiple lumen systems, the need to create leak-proof and secure connections is even greater, and it is also important to make the systems mistake-proof and user-friendly so that the proper connections can be made easily and without confusion.
Accordingly, although numerous catheter connection systems are known, few of these even address the particular problems associated with multiple lumen catheter systems, and none provide solutions for obtaining user-friendly, secure, leak-proof connections for multi-lumen catheters such as those utilized in peritoneal dialysis systems. Examples of such prior systems include those disclosed in patent references including U.S. Pat. Nos. 6,113,572; 4,929,236; 5,743,873; 5,129,891; 5,632,729; 5,399,165; 4,950,255; 5,417,672; 6,190,349; 5,667,490; U.S. Pat. No. D431,651; U.S. Pat. Nos. 5,190,529; 5,531,723; 4,781,185; 5,456,676; U.S. Pat. No. D303712; U.S. Pat. Nos. 6,254,589; and 6,190,372; Japanese patent references 2000-0045999; 1-171499; and 8-269224; and European Patent EP 553254 B1; all of these patent references incorporated herein by reference,
Another problem with catheters that are implanted in association with their utilization in peritoneal dialysis systems is that some of these catheters, such as the dual lumen catheter disclosed in WO 02/30489, have an implanted section which is made of a relatively hard material such as hard silicone so that they can maintain a proper configuration inside the peritoneal cavity when implanted. However, if such harder material is utilized in the part of the catheter that will be located external to the patient, it can create some discomfort for a patient. Although certain patents relate to catheters having a transitional area with an intermediate durometer, such as U.S. Pat. Nos. 6,135,992; 5,451,206; 5,348,536; 5,125,913; 5,792,124; and 4,739,768, all incorporated herein by reference, none have provided the necessary means whereby a multi-lumen catheter system can be simply and effectively made without such complex and difficult to manufacture materials, and yet provide the necessary internal durometer while maximizing comfort to the patient, being manually connectable, and providing a secure and leak-proof connection.
Further, other prior catheters utilized in procedures such as Continuous Flow Peritoneal Dialysis (CFPD) have had lumens which have a high interference with catheter connection adapter ports used to connect the patient to a source of dialysis fluid, and this makes connection even more difficult to accomplish.
Therefore, in addition to providing a connection assembly for multiple lumen catheters which is user-friendly and mistake-proof, so as to prevent the chance of an erroneous connection, it would be beneficial if the catheter used in connection with this assembly was more comfortable for the patient and could be connected easily with a minimum of resistance or interference.
Finally, in addition to providing a system of connections for multiple lumen catheters which can be made user-friendly and mistake-proof, it is also desirable to develop a system wherein the patient can stop or initiate the flow of dialysis fluid into or from the patient's peritoneal cavity, such as during the start or end of a dialysis procedure. Accordingly, it is also desirable to develop a user-friendly transfer set by which the user may easily and effectively set up the catheter tubing for dialysis and initiate or stop the flow of dialysis fluid when necessary during a dialysis operation involving a multiple lumen catheter.
Therefore, it is thus important to develop new catheters, catheter connection adapters and patient transfer sets which are user-friendly, mistake proof and which can provide secure and leak-proof connections, particularly for multiple lumen catheters containing at least two lumens, e.g., one for inflow and one for outflow, such as the implanted multiple lumen catheters employed for use in peritoneal dialysis systems.